Engine rattle

[kallekula]

Can’t hear anything else than a motor running
EDIT: maybe something. Get under there and bend/pull on everything you can see. Most common is loose heat shields. Give the cat some got bangs with a mallet too.

[jsrnsis]

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I found this heat shield had a bolt hole corroded away, but somehow it seems mounted there pretty well.



The front hydraulic mount, if it's in place with the weight of the engine, is the braided cable around it supposed to be a bit loose? Doesn't seem likely that that's the noise, but just something I noticed.

Giving the catalytic converter a good thump, no rattles, no play in the hangers. Heat shield directly above the cat is secure.

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I did notice this, the fuel line bracket is missing. I'm am pretty sure I remember taking that off when I took the head out, but have no idea where that piece would have went. Shaking the lines around as much as you'd want to be shaking fuel lines, when they tap the bracket, it's more of a knocking sound, but maybe when the engine is ~1500rpm its a resonating vibration.

I'll have to check it out tomorrow as well as remove the heat shield and check all the exhaust manifold bolts, but I think hands and feet losing feeling to the cold is enough for today.

[jsrnsis]

I would look at the heat shield as mentioned previously by volvolugnut. The metal can break around the mounting bolts. When you refitted the heat shield at the exhaust manifold, did you use the springs on the bolts?

Neil.

Well I found one of the heat shield bolts loose, tightened it up, still rattled.


Could there be any wastegate rattle if this is the condition of the linkage?

I added octane booster thinking it was maybe a combination of factors related to fuel and pinging. When I rev to 1500 could it start pinging briefly, and then the knock sensors and computer do their work?
If it was pinging, would it be more noticeable over the engine?
When I added the octane booster, I thought the rattle might have decreased in sound, but that might be wishful thinking.

Appreciate everyones replies to me figuring out this dumb problem.

[abscate]

Put a piece of thick padding between fuel lines and bracket, then zip tie them through the hole. Old piece of radiator hose would work , too.

[foggydogg]

I added octane booster thinking it was maybe a combination of factors related to fuel and pinging. When I rev to 1500 could it start pinging briefly, and then the knock sensors and computer do their work?
If it was pinging, would it be more noticeable over the engine?
When I added the octane booster, I thought the rattle might have decreased in sound, but that might be wishful thinking.

Appreciate everyones replies to me figuring out this dumb problem.

Knock sensor reactions measured in milliseconds, should be completely transparent to us end-users. Seems more like something from one of the tin bits, maybe the good Doctor can add his ears to the search.

[WhatAmIDoing]

Where the steel coolant line goes down to the turbo from the coolant bottle, there's a bolt that always seems to rattle out. Behind that is a heat riser that I always find seems to rattle.

[jsrnsis]

Where the steel coolant line goes down to the turbo from the coolant bottle, there's a bolt that always seems to rattle out. Behind that is a heat riser that I always find seems to rattle.

The bolt closest to the coolant tank on that steel line was tight, but definitely seems like a good place to check since there's a thin bracket up against a heat shield up against the exhaust manifold, and that rubber connection gives some resistance, so you might think you've tightened it.

The bracket further towards the turbo, where it should go up and over the heat shield and be bolted down, had actually broken. I bent the bracket so there was no chance of it rattling but left it in place incase I ever want to fix it.

[jsrnsis]

An update:
I tried giving the catalytic converter a good whack, and heard a rattle. Rattle doesn't appear when you try to wiggle or shake the exhaust, only on a whack.
Here's the sound:


While smacking the exhaust, I noticed that there was also a bouncing/vibration/rattle coming from the rear of the car. The exhaust hangers for the mufflers seem pretty stretched, and allow a lot of bouncing around. So I don't know if the material inside the cat is rattling, or if it's just amplifying the sound of the mufflers bouncing.

I took the above-turbo heat shield fully off and tightened the exhaust manifold "bolts". (Nuts are seized to the studs) I was actually able to snug two of them up.

I put everything together, tightened a few of the spark plug cover screws up, and the rattle/vibration sound seems to have gone away, or at least gotten less aggressive.

Here is the before:


Here is the after:


It's hard to tell in the garage with sound bouncing around, but at least to me it sounds better.
Now I hear some noise in the belt area...